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Accueil du site → Doctorat → Chine → 2021 → The Coupling Mechanism and Resilience of Soil Carbon,nitrogen and Water during Vegetation Restoration in the China’s Loess Plateau

Université de l’Académie chinoise des sciences (Centre de recherche sur la conservation des sols et de l’eau et l’environnement écologique) 2021

The Coupling Mechanism and Resilience of Soil Carbon,nitrogen and Water during Vegetation Restoration in the China’s Loess Plateau

李彬彬

Titre : The Coupling Mechanism and Resilience of Soil Carbon,nitrogen and Water during Vegetation Restoration in the China’s Loess Plateau

Auteur : 李彬彬

Grade : Doctoral Dissertation 2021

Université : Université de l’Académie chinoise des sciences (Centre de recherche sur la conservation des sols et de l’eau et l’environnement écologique)

Résumé partiel
Soil organic carbon(SOC),total nitrogen(TN),and soil water content(SWC)are the most critical elements in the ecosystem,which determine the ecological stability and sustainability.In the process of vegetation restoration for the arid and semi-arid Loess Plateau,SOC,TN,and SWC are the limiting soil resources,and their availability is the key to the success or failure of ecological construction in this region.Therefore,understanding the dynamics,coupling interactions and resilience of SOC,TN,and SWC during revegetation is an important link to clarify the stability and sustainability of the ecosystem in the Loess Plateau.Focusing on the ecological construction needs and frontier issues of arid and semi-arid regions in China,the soil-based multi-factor database related to SOC,TN,and SWC was constructed through historical data collection and field survey sampling,in which the planted forest,planted shrub and abandoned grassland after cropland conversion were selected as the research objectives.Then,the dynamics,coupling interaction and resilience of SOC,TN and SWC were studied,and we discussed how to realize the sustainable use and coordinated development of such resources,thereafter proposed planted vegetation management countermeasures based on the limiting resources which may provide scientific basis for sustainable management of planted vegetation in the Loess Plateau.(1)Revegetation exerted profound impacts on the SOC sequestration in deep soils horizons,and the extent varied with soil depths.Specifically,converting croplands to planted forest had higher SOC sequestration potential in the overall profiles,and the restoration age was the key factor.SOC stock increased significantly in the 0-100 and 100-200 cm horizons regardless land-use conversion types while SOC loss occurred in the 200-400 cm due to cropland conversion.Furthermore,the changes in SOC stock varied with restoration age,except for converting cropland to grassland.Specifically,SOC stock increased with restoration age in the upper 200 cm layers,whereas that in the 200-400cm horizons first increased and then decreased in the middle to later stages when converted to planted forest and shrub.Moreover,initial SOC stock and rainfall zones had significant effects on the changes of deep SOC stock.Interestingly,an accumulation of 1 Mg ha-1 in the upper 100 cm was associated with an approximately0.45 Mg ha-1 increase in the 100-400 cm depths.These results indicate that land-use conversion,particularly converting cropland to planted forest,changes deep(>100 cm)SOC stock,and restoration age should be taken into consideration when assessing deep SOC sequestration.(2)Revegetation enhanced TN stock in both top and deep soils.Planted forest and shrubs exhibited higher advantages than grassland in sequestering TN in entire soil profiles.

Mots clés : Soil functions ;Resilience;Synthesis ;Revegetation;Loess Plateau ;

Présentation (CNKI)

Page publiée le 16 février 2022